Introduction
A correct understanding of Epicurus' views as to desire and doubt is essential to grasping his philosophy as a whole. These should be considered together because it is thought by some that Epicurus held all doubt and all desire to be undesirable. We will examine first desire and then doubt, following up with a comparison of how in each case some are desirable and some are undesirable for a life of happiness based on pleasure.
Part I: The Classification of Desires
The Three Divisions
Among the most clear and authoritative presentations of Epicurus's doctrine of desire comes to us through Torquatus in Cicero's On Ends, Book One, Chapter XIII. There, Torquatus articulates the essential principle:
Quote"Nothing could be more useful or more conducive to well-being than Epicurus's doctrine as to the different classes of the desires. One kind he classified as both natural and necessary, a second as natural without being necessary, and a third as neither natural nor necessary; the principle of classification being that the necessary desires are gratified with little trouble or expense; the natural desires also require but little, since nature's own riches, which suffice to content her, are both easily procured and limited in amount; but for the imaginary desires no bound or limit can be discovered."
This tripartite schema—natural and necessary, natural but not necessary, and neither natural nor necessary—is the foundation of Epicurean desire theory. But the crucial and often overlooked point is that the classification is not primarily a moral command ("pursue these, avoid those"), but rather an analytical instrument. Its purpose is to give us clarity about the nature, cost, and potential for satisfaction that attaches to different types of desire, so that we can make wise and informed choices.
Natural and Necessary Desires
Desires that are both natural and necessary are those whose fulfillment removes genuine pain and whose neglect causes real harm. The desire for food when hungry, for shelter from cold and rain, for basic companionship, for freedom from physical suffering—these are desires grounded in our constitution as living beings. They are natural because they arise from what we genuinely are, not from social conditioning or arbitrary convention; and they are necessary because life cannot go well, and in some cases cannot continue, without their satisfaction. Crucially, as Torquatus notes, these desires are satisfied with "little trouble or expense." Nature has arranged it so that what we truly need is, by and large, accessible. A drink of water, a nourishing meal, a warm cloak, the company of a friend— in most situations these are not luxuries but within reach of nearly anyone who reflects clearly.
Natural but Not Necessary Desires
The second category—natural but not necessary—covers desires that arise from our nature but whose specific fulfillment is not required for well-being. The desire for pleasant food, for sexual gratification, for aesthetic enjoyment, for variety and richness in experience—these are genuine desires rooted in human nature and entirely appropriate. They are natural in that they are not fantasies invented by culture or social pressure; but generally they are not necessary in that the specific objects of these desires can be varied, and their absence does not cause the deep pain that the absence of food or shelter would cause. One may desire a particular delicacy, but the desire for nourishment can be met by simpler means. These desires can be pursued when circumstances allow for their pursuit to produce in the end more pleasure than pain.
Neither Natural Nor Necessary: Empty Desires
The third category is the most dangerous. Desires that are neither natural nor necessary are those Epicurus described as empty (kenai). These include the desires for unlimited wealth, for unlimited political power, for immortal fame, or for an inexhaustible parade of novel pleasures. What makes these desires empty is not that they are at first glance unlikely to be satisfied—it is that, by their very definition and inner logic, they are unlimited and thus cannot be satisfied. They are not grounded in nature's real needs; they are generated by false opinion and by social comparison, always promising a satisfaction that perpetually recedes and literally cannot be obtained.
A Critical Clarification: Epicurus Did Not Forbid Pursuit Beyond the Necessary
Here a vital clarification must be made, one that is frequently missed: Epicurus did not command that we only pursue natural and necessary desires. The classification is not a prescriptive law but a tool for understanding the risks and costs of what we pursue. If a person of means and leisure wishes to enjoy fine wine, elaborate cuisine, or beautiful art, Epicurus does not condemn this. What he warns against is allowing the pursuit of such things in an unlimited amount such as to enslave us—to make our happiness dependent upon them. The wise Epicurean uses this classification to navigate life with open eyes and to judge the likely results of the actions that are open to us, not to build a new cage of prohibitions.
The True Meaning of "Bad" Desires
A desire is bad in the Epicurean sense not simply because it fails to be satisfied on a given occasion. All of us experience unfulfilled desires from time to time, and this is a normal part of life. A desire becomes bad—genuinely harmful to flourishing—when it is empty: that is, when it is structured so that satisfaction is permanently impossible, when no amount of its object could ever suffice, and when its pursuit necessarily generates anxiety, envy, and dissatisfaction rather than genuine pleasure. The desire for enough food is natural and good; the desire for a quantity of wealth that by definition can never feel sufficient is empty and bad. The badness lies not in the desire being unfulfilled on one occasion, but in the fact that the desire is constitutionally incapable of fulfillment, and pursuing it is therefore not a path to pleasure but a path to chronic suffering.
Part II: Good and Bad Doubts
Epicurus and the Canonics of Knowledge
Epicurus was not only a philosopher of pleasure and desire; he was a remarkably careful thinker about the nature and limits of knowledge. Two of his Principal Doctrines speak directly to the question of what we can and cannot know with certainty. Principal Doctrine 23 states that if one disputes the testimony of all the senses, one will have no standard by which to judge anything; Principal Doctrine 24 extends this by noting that if we reject without distinction every clear perception, we eliminate the criterion by which we could correct any error at all.
Taken together, these doctrines establish a crucial Epicurean principle: there are things we can determine with certainty. In this category are primarily those things that we directly perceive and feel, but also those which we cannot perceive directly but of which we are persuaded by indirect evidence, such as the existence of invisible but indivisible particles as the natural basis of the universe. In the second category there are things we cannot determine with certainty, particularly the ultimate nature of distant or hidden phenomena about which we have insufficient evidence to choose from among various possibilities that are supported by direct evidence. Prudence requires that we know which is which, and that we refuse to treat uncertain matters with the false confidence that belongs only to the certain.
The Acceptability of Multiple Explanations
This epistemological humility has a direct practical implication that Epicurus stated with clarity. In his writings on natural philosophy, particularly in his Letter to Pythocles, Epicurus repeatedly allows that certain astronomical and meteorological phenomena may have multiple equally valid explanations. When the evidence is compatible with more than one account, it is not only permissible but intellectually required to hold all of them open rather than arbitrarily selecting one. Dogmatic certainty where certainty is not warranted is itself a form of error—an affront to the mind's commitment to truth.
On this position it is essential to be clear. Epicurus was not advocating for radical skepticism or for the view that nothing can be known. He was drawing a precise distinction: some questions have answers that can be determined by sensation and reason, and for these, confident assertion is appropriate and in fact necessary for a happy life. Other questions outrun our evidence, and for these, acknowledging multiple possibilities is the honest and philosophically correct response.
Good Doubts: The Courage to Challenge False Ideas
If there is a form of doubt that Epicurus celebrated, it was the active doubt that challenges false beliefs—particularly those that cause unnecessary fear and distress. The fear of the gods, the terror of death, the superstitious belief in divine punishment, the dread of a cosmos governed by arbitrary fate—all of these were, for Epicurus, false opinions responsible for enormous human suffering. To doubt these ideas, to challenge them with reason and evidence, to subject them to philosophical examination and reject them when found wanting: this was not merely intellectually praiseworthy but therapeutically essential. The entire project of Epicurean philosophy is in one sense an exercise in purposeful doubt—doubt directed against false beliefs that imprison human happiness.
A good doubt in the Epicurean sense, then, is one that challenges false ideas, opens space for accurate understanding, and thereby removes unnecessary suffering. Such doubt is active, reasoned, and courageous. Epicurus himself lived this principle, writing extensively against the prevailing religious fears of his time, against the belief in an afterlife of punishment, and against the view that the gods intervene capriciously in human affairs.
Bad Doubts: Corrosive Uncertainty and Paralysis
Not all doubt is liberating, however. A bad doubt in the Epicurean framework is one that refuses to acknowledge what can in fact be determined with confidence, that treats certain knowledge as if it were uncertain, or that spirals into an anxiety-producing paralysis incapable of any resolution. If a person refuses to trust the testimony of their own senses—if they doubt that they feel pleasure when they feel pleasure, or pain when they feel pain—they have severed the very thread by which they could correct error. This kind of corrosive, excessive doubt is not philosophical honesty but a form of confusion that undermines the foundations of knowledge and judgment.
Similarly, a bad doubt is one that becomes a source of ongoing existential anxiety rather than a productive spur to inquiry. Epicurus was clear that tranquility of mind is desirable. Doubt that perpetually disturbs the mind without moving toward resolution, that treats every question as insoluble and every judgment as arbitrary, is not philosophical virtue but a failure of nerve. The Epicurean wise person doubts when doubt is appropriate, asserts when assertion is warranted, and knows the difference.
Holding Open Questions Honestly
A final and important note: Epicurus did not demand that we always arrive at definitive answers. On questions where the evidence genuinely does not decide between competing accounts—as in many questions about the precise mechanisms of natural phenomena—the correct response is neither false certainty nor despairing agnosticism, but a disciplined openness. This is a form of intellectual integrity, not a failure of knowledge.
Conclusion
What emerges from a careful examination of Epicurus's thought on desires and doubts is a coherent and persuasive picture. The key in both cases is the distinction between what is grounded in reality—what corresponds to genuine nature, genuine evidence, genuine need—and what is empty, either because it is structured by false opinion to be insatiable, or because it mistakenly claims or avoids claiming certainty where the evidence supports one or the other. A good desire is one that is rooted in real human nature, capable of real satisfaction, and pursued without enslaving the soul to an unreachable goal; a bad desire is one that is constitutionally incapable of fulfillment. A good doubt is one that challenges false beliefs or honestly acknowledges genuine uncertainty; a bad doubt is one that corrodes the confidence we legitimately have, or generates anxiety without resolution. Epicurus's philosophy is focused on clarity: clarity about what we want, clarity about what we know, and clarity in understanding the difference.
Summary Table - Good and Bad Desires and Doubts
| Good | Bad | |
|---|---|---|
| Desires | Desires that are natural and necessary, or natural but not necessary when pursued with proportion and without enslavement to obtain more pleasure than pain. These desires are those that can in principle be satisfied and whose satisfaction genuinely removes pain or adds pleasure. | Desires that are "empty" — those which by their very nature and structure cannot be fulfilled, because they are not grounded in genuine human need but in false opinion, social competition, or unlimited ambition (e.g., the desire for inexhaustible wealth, unlimited power, or permanent fame). These desires are bad not because they happen to be unfulfilled on one occasion, but because no fulfillment is ever structurally possible. |
| Doubts | Doubt that actively challenges false beliefs responsible for unnecessary fear and suffering (e.g., fear of the gods, fear of death, superstitious dread); doubt that honestly acknowledges genuine uncertainty by holding multiple explanations open when the evidence does not decide among them. | Doubt that refuses to acknowledge what can legitimately be known with confidence (particularly sensory evidence, direct experience and logical deduction that is warranted by the evidence). This type of doubt destroys the very basis for knowledge and judgment, and spirals into paralyzing, anxiety-producing uncertainty without movement toward resolution. This doubt masquerades as a philosophical high ground but in practice prevents all sound judgment and undermines pursuit of a happy life based on pleasure. |